Stage expansion reaction turbines



July 19, 1960 c. B. MCLURE 2,945,619

STAGE: EXPANSION REACTION TURBINES Filed sept. 21. 1954 4 sheets-sheet 1 INVENTOR. (i4/@L 5 MC'LUEE July 19, C. B. MCLURE STAGE EXPANSION REACTION TURBINES Filed Sept. 21, 1954 4 Sheets-Sheet 2 1N V EN TOR. m3 gz @ARL 5. 4m/e5 C. B. MCLURE STAGE EXPANSION REACTION TURBINES 4 Sheets-Shadi 3 INVENToR. @APL B. MC'A UEE ,4 frog/v6 V5 July 19, 1960 Flled Sept 2l 1954 States Patent" Oce Patented July 19, 1960 STAGE EXPANSION REACTION 'I'URBINES Carl Ballard McLure, 21649 37th Ave. W., Seattle, Wash.

Filed Sept. 21, 195'4, Ser. No. 457,522

2 Claims. (Cl. 230-116) The present invention relates to power plants of the turbine type and is concerned particularly with a reaction type of turbine providing stage expansion which is especially suitable for internal combustion applications.

An important object of theinvention is to provide .a turbine having good eliciency and a high power output for its size. The design of the turbine is compact, and the parts are integrated so as to afford maximum strength for minimum weight.

A particular object ofthe invention is to provide a unique type of abrupt stage expansion of the combustion gases passing through reaction wheel ducts to increase the power output and eciency of the turbine. The design further contemplates utilizing twin reaction wheels to provide a high power output for a small and compact power plant.

An additional object is to locate twin compressor units and twin turbine wheels compactly on a common shaft with burners located between the two turbine Wheels.

A specific object is to provide stage expansion ducts of unique character in a reaction turbine wheel.

The foregoing objects can be achieved in a turbine unit having a casing defining at opposite ends ,chambers for reception of centrifugal blower rotors, and passages leading from the blowers to a burner or burners inthe central portionof the casing. From such central casing portion passages lead in, opposite directions to expansion turbine wheels. Such turbine wheels andthe compressor rotors are mounted on a common shaft extending through the casing. 'Ihe turbine Wheels have generally radiallyY directed passages, each including several portions which are interconnected, but between-which shoulders are provided to enable gases to expand abruptly as they ilow outwardly from one passage portion to the next. Such radiating expansion passages in the reaction wheels'discharge into exhaust ducts.

A preferred design of turbine construction is shown in the accompanying drawings.

Figure 1 is a top perspective view of the turbine with parts broken away to show internal structure. Y

Figure 2 is a'longitudinal sectional view through the turbine.

Figure 3 is an end elevation view of the turbine viewed from line 3-.3 of Figure 2, parts being broken away.

Figure 4 is a central transverse sectional view through the turbine on line 4--4 ofFigureV 2.

Figure 5 is a transverse sectional view through the turbine at the location of a reaction wheel, as designated by line 5-5 in Figure 2.

Figure 6 is an enlarged fragmentary section through a reaction wheel, taken along a radial plane, and Figure 7 is a sectional view on line 7-7 of Figure 6. Figure 8 is a sectional View through the turbine wheel on line 8-8 of Figure 7.

Figure 9 is a transverse sectional view through a turbine burner taken on line 9--9 of Figure 4.

The compact arrangement of the turbine of the present invention is shown best in Figures l and 2. The casing at opposite ends has housings 1 and 1', and between these are the casing portions 2 and 2 alongside the turbine reaction wheels. In the central portion is the housing 3 accommodating the burners. Thus the compressor housings and the turbine wheel enclosing portions of the casing are located inv symmetrical arrangement at opposite sides of the burner housing. Moreover, the generally cylindrical shells 30 for the burners extend diametrically oppositely from the central portion 3 of the casing so as to promote the symmetrical arrangement of the parts.

A shaft 4 extends axially through the turbine casing, and centrifugal blower rotors 10 and 10', respectively, are formed on its opposite ends and received in the housings 1 and 1'. These blower rotors carry radial vanes 11 and 11', respectively, which draw air inward through the air inlet apertures '12 and 12 in the ends of the casing and discharge such air centrifugally under pressure into the ducts 13 and 13', respectively. These compressors individually are of Yconventional type, but the arrangement of such centrifugal compressors with other components of the turbine assembly is unique. In kthe passages 13 and 13 are guide vanes 14 and 14 which are spirally inclined and assist in guiding air compressed by the compressor into the discharge passages 15 and 15',

respectively.

The turbine reaction wheels 20 and 20 are formed integral with the compressor rotors 10 and 10', respectively, and with the shaft 4. In addition, the webs 21 and 21 forming the bottoms of the grooves between the compressor blades 11 and 11', respectively, constitute parts of one side of each of the exhaust collector rings 22 and 22', respectively. From these collector rings exhaust discharge ducts 23 and 23 may extend. Undoubtedly there will be some pressure differential between the compressed ar passages 13', 13 and the exhaust collector rings 22 and 22', but the t of the webs 21 and 21 with the casing isY suliiciently close so that there will be little interchange between these spaces.

Also, an advantage of forming the blower rotors, the turbine wheels and the interconnecting shaft as a single structure is that any pressure differential between the blower and turbine sections at one end of the shaft, which tends to produce a thrust on the shaft is exactly balanced by an equal and opposite pressure differential in the blower and turbine combination at the other end of the shaft. Thus the thrust on the shaft is exactly equalized to avoid subjecting the shaft bearings to any appreciable thrust load. The thrust forces on the shaft will be reflected'only in tension or compression forces in the shaft parts of the same material such as Inconel metal.

Within the central portion of the turbine casing is the combustion chamber 31 within the casing part 3. The shellsl 30 for housing the burners 32 are shown as extending diametrically oppositely from the combustion space 31, so that the burners 32 open into such space, but it is not essential that theY burners'be located in this position so long, as the products of combustion are discharged into this space. The shaft 4 extends centrally through the combustion space and has a peaked ridge 40 located centrally of such space, which serves as a ilarne spreader as the shaft rotates to divide the ilow of combustion gases in opposite directions along the'shaft into passages 33 and 33' yfor flow into the ducts of the reaction turbine wheels.

The ducts of the turbine wheels which are the most important part of the present invention are shown best in Figures 6, 7 and 8. While these ducts are disposed generally radially of the turbine wheels 20 and 20', preferably with which they are parallel. Such disposition of the major portions of three of the ducts is shown in Figure 6. The trailing side 23 of such major portion of the duct is straight and parallel with a radius from which it is oiset, and such trailing side merges with the trailing side 24 of an outer duct portion inclined rearwardly in the direction of turbine wheel rotation to the major duct portion.

The sides and leading wall of the duct portion generally parallel to a radius of the turbine wheel expands in steps of which there are several, three being shown. The leading wall 25 of the innermost step diverges gradually outward relative to the trailing wall 23 of the gas discharge duct and is joined by an abrupt shoulder 26 with the next outward step 27. The leading wall of this step gradually diverges relative to the trailing wall 23 and the side walls of such steps also diverge gradually outward. At the outer end of step 27 is a further abrupt shoulder 28 joining the step 27 with the leading wall 29 of the outermost step. In this portion or step the side walls do not diverge appreciably, as is shown in Figure 8.

In order to direct the iiow of burning gas from the combustion space passages 33 and 33 into the radiating reaction passages of the turbine wheels the space alongside the turbine wheels between them and the casing is sealed. Thus, as shown best in Figure 2, support rings 34 and 34 are bolted to the inside of the casing and carry sealing carbon rings 35 and 35', respectively. Such carbon rings can withstand high temperatures and seal the space between the turbine wheels and the casing effectively While producing a minimum of friction.

In operation air is drawn into the intakes 12 and 12 by the blades 11 and 11' of the centrifugal turbine rotors and 10. Air compressed by these blowers passes into the collector passages 13 and 13', respectively, from which the air tlows into the passages and 15' and thence into their respective casings 30 around the shells 32 of their respective burners. Fuel is projected into the interior of these shells through nozzles 33, and the combustible mixture is ignited by spark plugs 34. The burning gas passing longitudinally inward through the burner shells 32 impinge upon the peaked ridge 40 of the shaft 4 and are divided into the passages 33 and 33 and the annular manifolds or header passages 36 and 36' of the turbine wheels.

From the manifold or header passages 36 and 36 the burning gases are distributed evenly to the first steps 2S of the radiating reaction turbine wheel passages. During flow outward through these passages the combustion gases expand gradually in the -rst step and then abruptly as they reach the shoulder 26 into the second step 27, gradually again as they pass through this second step, and once more abruptly as they pass shoulder 28 into the final step 29. As the gases pass beyond the inner generally radial portion of each duct the flow of gas is deflected into the portion 24 of the duct, directed rearwardly with respect to the direction of wheel rotation so as to produce a iinal thrust on the turbine wheel in a direction generally tangential to the periphery of the wheel. The reaction produced by the burning gases expanding in their travel through the turbine wheel passages and ejected in a trailing direction from the outer ends of such passages causes the turbine Wheels to rotate.

The gas discharged from the turbine Wheel passages is collected in the exhaust manifold 37 and 37 and passes out through the exhaust stacks 38 and 38. Power developed by rotation of the turbine wheels to a considerable extent is absorbed directly by the blower rotors 10 and 10 to compress the air used to support combustion of the fuel. The useful power developed drives gear 41 keyed to one end of the shaft, which may mesh with a gear 42 of any suitable gear train used for transmitting the power developed by the turbine wheels to the mechanism to be driven.

The various parts of the turbine can be cast to approximate shaft, and the clearance portions such as the outer edges of blades 11 and 11' and the outer edges of webs 21 and 21 with the correspondingly adjacent portions of the casing 1 and '1 can be machined accurately to the desired shape. The step portions 25 and 27 of the turbine wheel reaction passages are of circular cross section and can be ground by a rotating tool of special shape to the desired contiguration. The structure of the burners is conventional and conventional accessories (not shown) as may be required are utilized for supplying the fuel and the spark.

I claim as my invention:

l. In an internal combustion reaction turbine, a unitar rotor having on one side thereof generally radial centrifugal blower vanes with outlets from the spaces between their outer ends and on the same side of said rotor an air inlet leading to the spaces between said blower vanes,

. and said rotor having on the other side thereof a plurality of tubular reaction turbine passages extending generally radially of said rotor having inlet means at their inner end portions and with their outer end portions directed rearwardly in the direction of rotation of said rotor, and said tubular reaction turbine passages aring from inner portions toward outer portions.

2. In an internal combustion reaction turbine, a unitary rotor having on one side thereof generally radial centrifugal blower vanes with outlets from the spaces between their outer ends and on the same side of said rotor an air inlet leading to the spaces between said blower vanes, and said rotor having in the other side thereof a pluarlity of tubular reaction turbine passages extending generally radially of said rotor having inlet means at their inner end portions and with their outer end portions directed rearwardly in the direction of rotation of said rotor and said tubular reaction turbine passages having shoulders spaced lengthwise thereof forming said passages flaring in steps from inner portions toward outer portions.

References Cited in the tile of this patent UNITED STATES PATENTS 851,886 Hoover Apr. 30, 1907 1,616,646 Ardin Feb. 8, 1927 1,726,104 Harris Aug. 27, 1929 1,926,225 Birmann Sept. 12, 1933 2,256,198 Hahn Sept. 16, 1941 2,371,889 Hermitte Mar. 20, 1945 2,589,239 Fallon Mar. 18, 1952 FOREIGN PATENTS 287,701 Great Britain Apr. 26, 1928 383,966 France Ian. 23, 1908 1,027,121 France Feb. 11, 1953 

